一种新型有机非线性光学材料的光折效应及其产生机理

本文介绍了一种新近研制的光折聚合物。实验表明，除去吸收和反射，入射光束经聚合物后的第一布拉格衍射效率高达８６％，材料也显示出双光束耦合的净增益高于２４０ｃｍ＾－１。这些结果表明，这种新型研制的光折聚合物材料是替代无机光折晶体的实用材料。     

超导／半导兼容材料的制作及性能分析

介绍了几种结构合理的超导／半导兼容材料的制作技术及其测试结果，重点讨论了超导体（ＹＢＣＯ）与半导体（Ｓｉ，ＣａＡｓ）间缓冲层的选取，并对这几种复合材料的性能作了较详细的分析。     

电视节目资料管理及节目编排系统

系统采用XENIX操作系统和FoxBASE~+关系型数据库。本文简要介绍了该系统设计的基本原理、系统功能,并比较了XENIX多用户系统与DOS单用户系统的优缺点。     

基于Web Service的建材租赁管理信息系统的设计与实现

提高信息化管理水平对建材租赁企业的发展显得日益重要。在业务需求分析基础上,对系统进行设计,采用JavaEE架构,结合WebService技术及Hibemate＋Structs框架技术,以MySQL为数据库对建材租赁管理信息系统进行开发。该系统由Web服务和客户端应用两部分组成,具有跨平台应用、数据可共享与互操作、耦合度低、灵活性好、可扩展性和通用性强的特点,可向企业提供建材租赁管理信息服务。具有一定的推广价值。     

改进BP网络在航材需求预测中的应用

针对航材备件需求预测问题,在对影响航材备件需求量的多个因素进行分析研究的基础上,运用改进BP神经网络算法进行预测的仿真实验。实验结果表明,改进BP神经网络能够对积累的历史数据进行充分的应用,并且有较高的预测准确性。     

Influence of rainfall on the performance of bioretention systems modified with activated carbon and biochar

The use of bioretention areas is common in urban stormwater management, but their performance varies significantly depending on rainfall characteristics and design conditions. In this study, a pilot experiment using bioretention columns with different media (commercial activated carbon and river sediment-derived biochar) investigated the influence of rainfall on bioretention performance. The results indicated that the runoff volume retention ratio (R_v), which included the runoff purified and discharged at the bottom of the column, and the runoff retained in media during rainfall event, decreased significantly with increases in the rainfall event return period (p < 0.05). The R_v of the activated carbon and biochar columns decreased with a 2-yr return period and then fell further with a 50-yr return period. Porous material has been shown to improve the water-holding capacity of bioretention media, but it did not result in an improved R_v under heavy rain that exceeded the 2-yr return period. With the increase of the return period from two to 50 yr, the mass removal efficiency (R_L) of total phosphorus and phosphate illustrated a clear decreasing trend in all columns. The total nitrogen, ammonia and nitrate removal did not show a clear trend with return periods because of transformations among different forms of nitrogen and similar saturation periods during the different rainfall events. The influence of the return period on chemical oxygen demand (COD) removal was related to whether the inflow COD reached maximum COD removal capacity of the bioretention media. Under a rainfall event with a specific return period, there were no significant differences in the R_L of all nitrogen species and COD among the different columns (p > 0.05). The addition of adsorptive material, such as activated carbon and biochar, may not be the key factor for improving nitrogen and COD removal under heavy rain that exceeds the 2-yr return period. The bioretention performance of phosphorus removal from urban stormwater runoff could be improved by replacing or adding media with high adsorption capacity, but these improvements would not be significant under heavy rain that exceeds the 2-yr return period. The results provide some reference for evaluating bioretention performance and optimizing bioretention design in the future.     

中碳结构钢件的锻造成形与锻后调质一次完成的热加工新技术

本文是利用“形变诱发析出”原理通过控制热变形成形过程获得一种能在过冷分解时使碳化物呈颗粒状弥散析出的形变奥氏体状态,又通过控制冷却抑制先共析铁素体的析出,同时促进碳化物颗粒的析出,从而得到100％调质型组织,它达到了传统工艺的水平。     

Thermal expansion of Pyros from 20 to 1273 K

Pyros, which is a Ni-base alloy (82% Ni, 8% Cr, 4% W, 3% Mn, and 3% Fe), has been used extensively in France since 1926 as a temperature sensor and as a reference material for thermal expansion measurements. In this paper we present recent data on the expansion and expansivity of Pyros from 20 to 1273 K. Expansivity results, obtained by taking the derivative of a cubic-spline polynomial fitting performed to the L/L experimental data, show that Pyros is a stable material in the 20 to 1273 K temperature range. Furthermore, since the expansivity values are similar to those of steels, Pyros should be of special interest to laboratories which are concerned with expansion measurements on steels. Therefore, we suggest that Pyros be considered as a suitable reference material for thermal expansion measurements on steels, and until more accurate results are obtained, we propose our results as reference data between 20 and 1273 K.Paper presented at the Ninth Symposium on Thermophysical Properties, June 24–27, 1985, Boulder, Colorado, U.S.A.     

Fabrication of Nano-TiO2 Coating for Dye-Sensitized Solar Cell by Vacuum Cold Spraying at Room Temperature

Deposition of nanocrystalline TiO₂ coating at low temperature is becoming more attractive due to the possibility for continuous roll production of the coating for assembly lines of dye-sensitized solar cell (DSC) at a low cost. In this study, porous nano-TiO₂ coating was deposited by vacuum cold spraying (VCS) at room temperature on a conducting glass substrate using commercial P25 nanocrystalline TiO₂ powder. The microstructure of TiO₂ coating was characterized by field emission scanning electron microscopy (FESEM) and nitrogen adsorption test. A commercial dye (N719) was adsorbed on the surface of TiO₂ particles within the coating to assemble a DSC. The cell performance was evaluated by employing simulated solar light at an intensity of 100 mW/cm². The results showed that TiO₂ coating was deposited by the agglomerates of nano-TiO₂ powders. The Brunauer-Emmett-Teller (BET) test of the as-sprayed TiO₂ coating yielded a porosity of 49% and an average pore size of 17 nm. The assembled solar cell yielded a short-circuit current density of 7.3 mA/cm² and an energy conversion efficiency of 2.4%. The test results indicate that VCS was a promising method to deposit nanocrystalline TiO₂ coatings at low temperature applied to DSCs. This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain Montavon, Ed., ASM International, Materials Park, OH, 2007.     

低碳钢显微结构的EBSD表征

近年来,新开发的电子背散射衍射技术将多晶材料的显微组织、微区成分与结晶学数据分析联系起来,能对晶界类型、取向、位向差和结构及其分布进行观察、统计测定和定量分析,从而建立了晶界结构、取向和织构等与多晶材料性能的定量和半定量关系,成为现代材料研究的重要实验技术。笔者结合低碳钢生产中的一些实际问题,扼要介绍了电子背散射衍射技术中的晶体取向图在多晶材料显微结构表征中的应用。